This is a request for renewal of a program on the neuroanatomical basis of cognition and behavior initiated in 1983, and renewed in 1986 and 1991. The purposes of the program remain: (1) to elucidate by means of hypothesis-driven research the relation between large-scale human neural systems, on the one hand, and memory, vision, emotion, language, and decision-making, on the other; and (2) to maintain and expand a neurological Patient Registry, which now constitutes a unique resource for neuropsychological research. The systems targeted by the Program are seen as networks of cortical regions and subcortical nuclei; the subjects are neurological patients with focal lesions in components of the putative networks, studied both neuropsychologically and with advanced in vivo neuroimaging/neuroanatomical methods; and the lesions are used as probes to test hypotheses concerning the role of varied neural components in specific functions. The lesion approach is complemented by experimental neuroanatomical studies aimed at elucidating the intrinsic structure and interconnection pattern of the systems studied with lesions. As in previous periods, the investigators have contributed novel findings in every project, developed new techniques for cognitive neuroscience, and now propose to test a set of exciting new hypotheses. Elucidating the neurobiology of cognition and behavior is the last frontier in the life sciences and a high priority for fundamental science. The studies proposed here, however, also contribute to progress in the understanding, diagnosis, and management of neurological and psychiatric conditions, such as cerebrovascular and Alzheimer's diseases, head injury, cerebral tumors, epilepsy, and sociopathy. Moreover, several neuroimaging and cognitive tools developed here for experimental purposes, have found a practical use in the management of these conditions.